Twyer.



L. E. THOMPSON TWYER.

APPLICATION FILED JULY 14.

Patented Feb.11 ,1919@ LESTER E. THOMPSON, 0F MEDFORD, MASSACHUSETTS.

TW'YER.

N Specification of Letters Patent.

Patented Feb. ii, leis.

Application filed July 14, 1917. Serial No. 180,690.

To all whom it may-concern Be it known that I, LESTER E. THOMPSON, a citizen of the United States, and a resident of Medford, county of Middlesex, and-State of Massachusetts, have invented an Im provement in Twyers, of which the following is a specification.

My invention relates to boilers and has specific reference to such boilers equipped with mechanical coal feeding means and to which the air for combustion is" applied under pressure. a l 1 Steam boilers-of large ca acity are customarily' equipped with apparatus or stokers, whereby-the coal used as fuel introduced in the in box under the boiler automatically and iilechanically by the use of reciprocating plungers, which operate to force the coal from a hopper through con.-

duits into the fire box, traveling belts which serve to carry the fuel under the boiler, or by other similar means.

The coal is introduced into 'thefire box, as heretofore stated, in channels or conduits, andbetween each coal channel there is disposed means for the introduction of air into the coal, whereby the coal may unite with said air and burn. The means commonly employed for the admittance of air into the coal consists of a series of flatplates or twyers, as they are commonly termed, super-' imposed in stepped rows one above the other between each of the coal channels. The twyers have suitable openings therethrough connecting with the air box, of which the rows of twyers form a-wall, whereby air may flow from said air boxes into the mass of coal;

The twyers, as commonly constructed, are interlocking, and the top twyers of any series or row serves to lock all the lower twyers against displacement therefrom; and to remove any intermediate twyers in the series, it is necessary to remove in successive order the twyers'locatedabove the particular one, 'beginning with the top twyers.

When it is considered that these twyers are disposed in the hottest part of the fire box, where the temperature may run as high as 4,000 degrees Fahn, and when it is also considered that these twyers, for cheapness, are made of cast iron, it is seen that due to the action of the heat the individual twyers of the series can have but a short life and that it is necessary that constant replacements be made. The action of the intense heat upon the cast iron located, as it is, in

.the reducing atmosphere of the fire box serves to burn the cast iron and make it extremely brittle and fragile. Inasmuch as the lower twyers of the series are subjected to well as the burnt twyers situated at the bottom of the row; so that in the replacement of the burnt out twyers, many more twyers of this series are broken, and it frequently happens that over half of the series have to be replaced because of the breaking of the twyers in their removal from the series.

, In view of the above difiiculties, it is an object of my invention to provide a twyer adapted for a position in a series of twyers, whereby said twyer may be extracted or removed from said series without the dis-.

turbance or removal of any other twyer of said series. I accomplish this result of my invention by the provision of means whereby each twyer may be independently pinned, or otherwise secured to the walls of the wind box or channel, and which pin or other securing means is adapted for ready removal independently of any other pin or securing means to admit of the consequent removal of any twyer of the series independent of any other twyer of said series.

In the customary form of twyer the locking means provided between any two twyers consists of a plurality of projections in one of said twyers adapted to fit in a corresponding plurality of indentations in the other of said twyers. When the said twyers are subjected to heat, the twyer consequently expands; and due to the unequal expansion of the two twyers, there results atensional stress in both of said twyers, which resulted in the continual breaking of said twyers.

Another object of my invention is to provide means associated with the means sethe expansion of the twyers due to heat do not operate to cause stresses in any part of the twyer which would tend to rupture the same.

Inasmuch as these twyers are interposed between the channels of coal, it is desirable that the greater quantity of air issuing through the ports of the twyers be directed in a sidewise direction into the mass of coal, with but a small proportion of the total volume of air passing through said twyers being directed directly into the fire box; and consequently, another object of my 1nvention is to provide means to accomplish this result.

Figure 1 illustrates a side view partly 11]. section of a fire box and a series of twyers constructed according to my invention.

Fig. 2 illustrates a partial front view of the fire box shown in Fig. 1.

Fig. 3 is a plan view of the twyer.

Fig. l is a bottom view of the twyer shown in Fig. 3.

Fig. 5 is a sectional detail of the air passage taken along lines 55 of Fig. 1.

Fig. 6 is a developed view of the air ports in the twyer.

Fig. 7 is a sectional detail showing relation of twyer and wind box.

As here shown. the twyer comprises a flat plate or block, having a pointed toe portion 10 and rearwardly extended cars 11, forming .a heel portion through which a pivot pin or bolt 12 is adapted to be passed to secure said twyer to the said walls 13 of the wind box. The twyer is formed of a width greater than that between the ears 11 and said side portions have beveled or tapered ends ll adapted to conform with the taper of the walls of the wind box 13, and to rest on the outer portion thereof to support the said twyer and maintain the same in a substantially horizontal plane. Between the rearwardly extended cars 11 the" twyer is formed with an inwardly extending recess 15, which serves as a conduit for the conduction of air to the passages in the twyer above and also to lighten said twyer. The toe portion 10 is formed with a series of teeth 16 the tops of which rest on the top face of the next lower twyer in this series and the space between which teeth forms a conducting channel for the discharge of air into the coal from the air box. Said teeth are raised from the plate structure as shown more clearly in Fig. 5, whereby the back of said twyer and the next lower one. in the series form a conducting channel thereto, and the construction of which also serves to lighten said twyer.

T he air passage of said twyer is constructed in a novel manner, in accordance with an object of my invention. whereby the greater part of the air issuing through the twyer into the. fire box is directed to the sides of the twyer and into the coal channels. Said teeth are formed with a progressively decreasing pitch and depth from one side 17 to the'flat toe portion 10 through the extent of which the pitch and depth of the teeth are maintained constant, from which the teeth increase in pitch and depth in a progressive manner to the other side portion 17. WVith this construction of tooth the maximum area of air passage formed thereby is located at the sides of the twyer, and consequently the greater part of the air discharged therethrough is directed into the greater mass of coal located at the sides thereof.

The twyers constructed as described are adapted to be placed in a series between the walls of the wind box, as shown more clearly in Fig. l, and each twyer is independently pinned or secured to such walls. It is seen that with this construction, when the bot tom twyer or any twyer of thisseries becomes so burnt or broken that replacement is necessary, the broken twyer may be removed from the series by the simple removal of its securingpin or bolt 12 without disturbing in any degree any other twyer in the series, whereby the removal of any twyer does not cause the breaking of several other twyers, as has been heretofore the case.

It is also seen that, with the twyer secured against displacement at but one point, the forces set up in said twyer due to the heat can in no way operate to injure the twyer.

I claim:

1. In combination with the wind box of a boiler, of a series of superimposed twyers therein and means for independently looking said twyers to the wall of the wind box.

In combination with the wind box of a boiler, of a series of superimposed twyers therein and means for maintaining each of said twyers in position in said series independently of any other of said twyers.

t). In combination with the wind box of a boiler, of a series of superimposed twyers therein and means securing said twyers in position 1n the series adapted to permit the removal of. any twyer independent of any pendently secure each twyer in place in said wind box.

6. In combination with the wind box of a boiler, a series of superimposed twyers therein, of a pin extending through each of said twyers and the walls of said wind box whereby each twyer is secured in place therein and whereby each twyer may be recomponent part of 'said twyer having a ta- "pered portion adapted to engage a sloping side wall'of said wind box to maintain said twyer in a substantially horizontal plane therewith, said pin and sloping portion of the twyer providing means or securing the twyer in the wind box independent of any of the twyers of the series.

8. A twyer adapted to comprise one of a series of superimposed twyers in the wind box of boiler having a toe portionand a heel ortion said toe ortion havin a1r assa es in the face thereof and said heel portion providing means whereby the twyer may be detachably secured in position in the wind box of a boiler independently of any other of the twyers comprisin said series.

9. A twyer adapte to comprise one of a series of superimposed twyers in the wind box of a boiler having a toe portion, a heel portion and beveled side portions, said toe portion having air passages in the face thereof, said heel portion providing means whereby the twyer may be detachably secured in position in the wind box of a boiler independently of any other of the twyers of said series and said beveled side portions providing meanswhereb said twyer may maintain a predetermine position with regpectto the sloping side walls of the wind 10. A twyer adapted to be placed in a series of superimposed twyers in thewind box of a boiler, and means arranged to secure said twyers therein permitting a movement thereof independently, of any other.

of the twyers in the series.

11. A twyer adapted to be placed in a series of superimposed twyers in the wind box of a boiler, and means arranged to secure said twyer therein permitting an expansion or contraction thereof unrestricted by any other of the twyers of the series.

12. In combination with the Wind box of a boiler of a series of superimposed contiguous twyers, and means independently securing said twyers in position permitting the independent expansion of said twyers.

13. In combination with the wind box of a boiler, of a series of superimposed contiguous twyers and means independently securing said twyers in position permitting the unrestrained expansion of said twyers.

14. In combination with the wind box of a boiler, of a series of superimposed con tiguous twyers, and means independently securing said twyers in position permitting the independent and unrestrained expansion of said twyers.

15. A twyer adapted for use in a series of superimposed twyers in the wind box of a boiler having means whereby it may be se cured in position in said series independent of any other twyer of the series.

16. A twyer adapted for use in a series of superimposed twyers in the wind box of a boiler and means permitting the removal of said twyer from said series independently of any other twyer of said series.

17. A twyer adapted for use in a series of superimposed twyers in the wind box of a boiler and means securing said twyer therein independently of any other twyer 1n the series and permittingthe removal of saidv twyer therefrom "independently of any other twyer of the series.

In testimony whereof I have signed my name to this specification in the presence-of two subscribing witnesses.

" LESTER E. THOMPSON. Witnesses:

H. B. Dim, T. T. Gnnnnwoon. 

